摘要 |
A gas compressor, particularly of the kind for boosting pressur in gas transmission lines, has an impeller (30) mounted on a shaft (22) located between two bearings (24) with the gas space (40) surrounding the impeller (30) being separated from the bearings (24) by dry gas seals, including at least primary dry gas seals (52a, 52b, 54a, 54b). The primary dry gas seal (52b) adjacent the discharge end (14) of the compressor is of larger diameter than the corresponding seal at the inlet end (12) of the compressor so that pressurized gas acting on the respective rotary parts of the dry gas seals urges the shaft (22) towards the discharge end (14) of the compressor and thus counteracts dynamic forces on the impeller (30). |